I have a 5-year old Samsung 8" tablet which is still working just fine, and a new Samsung 7" with a slightly better screen quality. I prefer the 7" as it is more compact. It fits on my thigh just perfectly, just like a kneeboard or I have a yoke mount. I like using it in portrait mode with 'track up' but works just as well 'North up'. Unlike the horribly bulky larger tablets I see, it doesn't obscure any of the instruments OR the outside view. I just hate to see tablets stuck up where you can't see traffic coming. SkyDemon is a VFR product and when using it, 90% of your attention ought to be outside the aircraft, with the occasional glance at the GPS to confirm your position. If you're IMC, then you should be doing something different, principally keeping your scan going. If your tablet is obscuring your instruments, then you're not flying IMC properly.
In terms of battery life, the Samsung 7" gets me 2 x 2.5 hour flights easily without need of an external power source or leads. The internal GPS is just fantastic inside a metal aircraft. I can use my phone to give a mobile capability to the tablet, but have never felt the need in flight.
Leads all over the place are another pet hate of mine. Apparently, there was a guy who ditched a PA28 near Alderney. Last seen by his passenger, allegedly he was struggling with a load of wires and was unable to get out.
The best solution is to panel mount the device.
TOO